Abnormal Plug And Play Operation For Vga - Acer RA19WAANU Service Manual

ACER X193HQ
26
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5.7 Abnormal plug and play operation for VGA

Check the voltage on P302 pin9 that is power DC 5 V.
Check the signal on P302 pin12, 15 that is serial data
Failure Point
1) Printed wire broke among I305 pin5,8,R320,R321and
P302 pin12,15
2) I305 maybe failure.
3) R424,R425 is open.
4) R328 or R330 or C330 or C331 is open or short.
5) R320 or R321 or D308,D306 is open or short
Confirm the host computer supplies DDC2B mode.
OK
OK
Check the voltage on Q307 pin1 that is power DC
3.3V.
OK
/ clock signal.
OK
Check the output signal of serial data / clock on I305
pin5, 8.
OK
NG
Failure Point
The host machine is not communicatiog in DDC2B mode.
NG
Failure Point
TheVideo cable is failure.
Failure Point
NG
1) Printed wire broke between Q307 pin3,D325 and
P302 pin9
2) R369,R372,R363 is short or open.
3) D325 is failure or Q307,I304 is failure.
NG
Failure Point
The Video cable is failure.
Failure Point
NG
I305 is failure.